Generation Mobile Phone Research Articles

Triple band self-decoupled MIMO antenna pair for 5G communication

A two port multiple input multiple output (MIMO) antenna with self-isolation is proposed for the application of fifth generation (5G) mobile phones. In this antenna, feeding ports that are inherently isolated across a bandwidth without the need for extra decoupling components directly excite the MIMO antenna. An approach involving the creation of common and differential modes utilizes a mode-cancellation technique to comprehensively understand the self-decoupling mechanism on a physical level. The proposed self-decoupled antenna pair exhibits about 22 dB isolation across the triple band 2.58 GHz to 2.84 GHz, 3.4 GHz to 3.9 GHz and 4.3 GHz to 4.6 GHz, respectively. According to the experimental findings, the proposed MIMO system may offer better than 22 dB isolation across all ports and a respectable level of overall gain 1.9 dBi, 3.77 dBi and 2.9 dBi across 2.58 GHz to 2.84 GHz, 3.4 GHz to 3.9 GHz and 4.3 GHz to 4.6 GHz. A suggested design method, with its advantages of self-decoupling, simple structure, high efficiency and triple band demonstrates amazing upcoming 5G highly integrated MIMO antennas for 5G devices.

An improved Mini Antenna Designed at 60GHZ for a New Generation Mobile Phone

Five-generation (5G) communication systems are being required to meet the needs of small, high-speed, and big bandwidth systems [2]. This paper simulates and designs a 60GHZ rectangular micro strip patch antenna. The proposed antenna resonates at 60GHZ with a return loss of -32.126 dB, efficiency of 87.7119%, and gain of 6.96485 dBi. The patch is 2.726 x 2.364 x 0.125 mm. The radiating patch and the 50Ω micro strip feed line are matched using an iset feed transmission line approach. A Roger RT Duroid 5880 substrate, with a height of 0.125mm and a dielectric constant of 2.20 and a loss tangent of 0.0009, was selected in the design. The Advanced Design System (ADS) was used to compute the antenna's parameters and evaluate the results of simulations.

The Marketing Strategy of iPhone Series in Chinese Market

Apple has become the world leading mobile phone producer since it launched its first generation mobile phone in Chinese market. Literature survey, case analysis and 4P theory has been adopted in this paper, aims to analyze Apples successful experience in Chinese market, and provides Chinas mobile phone enterprises with possible suggestions to improve competitiveness to break into the global market. The reason why iPhone can quickly open the Chinese market and continue to hold a stable market share as its good performance and fashionable appearance, as well as series of marketing strategies. Nowadays, Chinese mobile phone producers have many problems with their products, such as poor quality, low technology level, brand missing etc., the marketing strategy that adopted by Apple can use for reference for Chinese mobile phone producers. By improving product quality, strengthening product design and technology innovation, bundling products with services, the Chinese mobile phone enterprises improve their competitiveness in the global market.

Electromagnetic field exposure to human head model with various metal objects at sub-6 GHz frequencies

ABSTRACT In recent years, the interactions of metal objects in human body with electromagnetic fields caused by devices working at fifth-generation (5G) frequencies have been studied by various researchers. A motivation behind this research was to evaluate the human body absorption of electromagnetic energy operating at sub-6 GHz 5G applications. According to this, the specific absorption rate (SAR) caused by new generation mobile phones was investigated in human heads wearing metal-framed spectacles and having metallic implants or earrings to analyse electromagnetic field exposure. A realistic human head model, including some metal objects, was numerically calculated, and analysed in terms of non-ionizing dosimetry. Simulations were carried out with the finite integration technique (FIT) based commercial software in the frequencies of 0.9, 1.8, 2.1, 2.45, 3.5 and 5 GHz, respectively. The maximum SAR of 14 × 10−5 W/kg for 10 g average tissue was calculated at 2.45 GHz frequency in the head model with earrings. The highest electric field strength of 0.52 V/m was observed at a 1.8 GHz frequency in the head model with all metal objects equipped. Results show that metal objects such as spectacles, dental implants and earrings can cause an increase in the SAR values for external biological tissues, and metal objects can behave as a kind of shield for deeper tissues. However, the obtained values are below the limits of international organisations.

Distortion Analysis of RF Power Amplifier Using Probability Density of Input Signal and AM-AM Characteristics

When confirming the ACLR (adjacent channel leakage power ratio), which are representative indicators of distortion in the design of PA (power amplifier), it is well known how to calculate the AM-AM/PM characteristics of PA, input time series data of modulated signals, and analyze the output by Fourier analysis. In 5G (5th generation) mobile phones, not only QPSK (quadrature phase shift keying) modulation but also 16QAM (quadrature modulation), 64QAM, and 256QAM are becoming more multivalued as modulation signals. In addition, the modulation band may exceed 100MHz, and the amount of time series data increases, and the increase in calculation time becomes a problem. In order to shorten the calculation time, calculating the total amount of distortion generated by PA from the probability density of the modulation signal and the AM (amplitude modulation)-AM/PM (phase modulation) characteristics of PA is considered. For the AM-AM characteristics of PA, in this paper, IMD3 (inter modulation distortion 3) obtained from probability density and IMD3 by Fourier analysis, which are often used so long, are compared. As a result, it was confirmed that the result of probability density analysis is similar to that of Fourier analysis, when the nonlinearity is somewhat small. In addition, the agreement between the proposed method and the conventional method was confirmed with an error of about 2.0dB of ACLR using the modulation waves with a bandwidth of 5MHz, RB (resource block) being 25, and QPSK modulation.

Directional link attenuation in millimeter-wave range based on empirical model modification

The upcoming fifth and next generation mobile phone systems will use not only the frequencybands of sub-6 GHz but also the millimeter-wave and terahertz bands. From a practical viewpoint,this approach requires the use of directional antennas or beamforming systems. To ensure greaterenergy efficiency of the wireless link, the radio beams on the transmitting and receiving sides shouldbe aligned ones. Path loss models are commonly used for designing the radio communication systemsand networks. However, in the literature, there are no adequate methods of attenuation modellingavailable for the cases of misalignment of antenna beams. In this paper, a method of modifying the pathloss model, based on a multi-elliptical propagation model, is proposed. For this purpose, dedicatedsoftware was developed in the MATLAB environment, which was used to conduct simulation tests.In the remainder of the paper, exemplary results of the adaptation of empirical path loss models inthe range of millime-ter-waves are presented, which were obtained using the developed program.Keywords: wireless communication, radio wave propagation, path loss models, multi-ellipticalpropagation model, directional antennas, directional radio link, millimeter waves, 5G systems,simulation studies

Specific absorption rate assessment of fifth generation mobile phones with specific anthropomorphic mannequin model and high‐resolution anatomical head model

With the spread and application of the fifth generation (5G) of mobile communication technology, the number of 5G mobile phone users increase rapidly. The traditional safety standard of electromagnetic radiation of mobile phones was set two decades ago, in which a homogeneous specific anthropomorphic mannequin (SAM) head model with standardized size and shape is utilized for specific absorption rate (SAR) evaluation. The SAM model has been proved conservative for SAR evaluation of 2G, 3G and 4G mobile phone antennas. However, it needs to be validated whether it is still suitable for SAR evaluation of 5G mobile phone antennas. A high-resolution anatomical head model with tissues including muscle, skull, cerebrospinal fluid and brain is developed in this paper. The SAR values of three different generation mobile phone antennas are simulated by utilizing both the SAM model and the high-resolution anatomical head model to assess their applicability. Numerical simulations show that the anatomical model may produce a higher SAR value than the SAM model for a 5G mobile phone antenna. So new head model may need to be developed for the SAR evaluation of 5G mobile phone antennas.

Implementation of an enhanced 32 channel 256 Gbps DWDM based Radio over Fiber optical system for constricted channel spacing employing Fiber Bragg Grating

Radio over Fiber (RoF) systems form a crucial component of fifth generation (5G) mobile phone networks targeting higher capacity and better cost effectiveness in the existing telecommunication system architecture. An enhanced 32 channel 256 Gbps DWDM based RoF optical system incorporating DCF and FBG as dispersion compensators has been analyzed in Optisystem software, capable to transmit data at 8 Gbps per channel offering optimum signal reception over distances of 60 km and 120 km. Maximum Q factors of 15.34 and 15.97 were obtained for narrowed 50 GHz channel spacing for 60 km and 120 km respectively in 32 channel mode. The proposed system delivered very high Q factor of around 79 for 50 GHz channel spacing when operated in 8 channel mode at 4 Gbps per channel bit rate. Appreciable FWM side band power level reduction of average 6 dBm was also shown from the obtained spectrums. The transmission quality for long haul traversal (120 km) and constricted channel spacing (50 GHz) was observed to be much better than the existing WDM-RoF architectures.

Use of the sensors of a latest generation mobile phone for the three-dimensional reconstruction of an archaeological monument: the survey of the Intihuatana stone in Machu Picchu (Peru’)

The survey of archaeological monuments presents particular needs and difficulties. Such surveys must in fact be as complete, geometrically correct and accurately geo-referenced as possible. These needs, however, often face problems of difficult accessibility, the need for rapid timing and complex logistical conditions. The latest generation of mobile phones are equipped with ultra-high resolution cameras up to 100 megapixel. Although they do not have the geometric characteristics of professional cameras, they can be used advantageously for the reconstruction of three-dimensional models using Structure from Motion methodologies . At the same time, the latest mobile phones are equipped with GPS/GNSS chips that allow a postprocessing of their positioning allowing to reach decimetric/centimetric accuracies. The use of sensors integrated in a mobile phone greatly simplify the survey both in terms of transportability but also in terms of authorizations by the competent authorities as the equipment is exactly the same that most tourists who visit the sites themselves bring with them. The approach proposed and made possible by these combined features in a latest generation mobile phone have been tested for a rapid survey of the Intihuatana stone in Machu Picchu (Peru), a site with considerable logistical and organizing complexity.

MINIMAL PLANNER MOBILE PHONE MIMO ANTENNA WITH ENHANCED GAIN

Background. Previously, Many MIMO designs were presented for 4G applications. Out of stated 4G MIMO antennas, few designs presented are not suitable for use in mobile phones due to their large size as compared to the standard sizes of current generation mobile phones. The rest, Ceramic based mobile phone antenna and a multi-band MIMO antenna with PIFA structures have significant heights and non-planner structure which makes them unsuitable for mobile phones as they are getting thinner with advancement in technology. Some MIMO antennas were designed with simpler structure and suitable size but they do not have adequate bandwidth. Here there is a need to develop a MIMO system with an adequate bandwidth to cover all 2G, 3G and 4G bands as well as compact to be suitable for mobile communication.Objective. The purpose of the paper is to design a compact planner MIMO antenna Suitable for Mobile communication with enhanced gain and an enhanced bandwidth to cover all 2G, 3G and 4G bandsMethods.i. A monopole was designed with proper dimensions, which was designed to operate at focus recurrence of 1.8GHz. That covers the wide scope of data transfer capacity from 1.1 GHz to 2.7 GHz at -9 dB reference line. Then an inverted L shape structure known as SIR stub technique is used to enhance the bandwidth.ii. The inverted L shape structure which is extended from the ground plane is put around the monopole which generates the low resonant frequencies and also broadens the bandwidth. Bandwidth is broadened to 0.8 GHz to 3.5 GHz.iii. For the purpose of more impedance matching, a small patch is etched from the ground plane opposite to the feeding and all the parameters are optimizedResults. that lower 0.9GHz radiation pattern is omnidirectional while at higher frequencies it is quasiomnidirectional, a steady gain greater than 2.8dBi over the entire frequency band i.e from .8 GHz to 3.5 GHz, avery high gain of 6.7 dBi at 0.9 GHz. The compact wide band planar MIMO antenna has over 80% efficiency over most of the working recurrence For handy application ECC value less than 0.5 is adequate for mobile phones. The measured ECC is less than 0.36 over complete operating frequency band, which is all right for mobile phonesConclusions. The paper presents compact planner two port MIMO antenna with wideband width and high gain. The proposed antenna achieved a wide bandwidth from 0.8GHz to 3.5GHz covering 2G/3G/4G bands and Wi-Fi (2.45GHz). High isolation between antenna elements, lower ECC and high diversity gain makes the design of the compact planner wide band MIMO antenna a suitable possibility for mobile phone applications.

Melatonin Modulates NMDA-Receptor 2B/Calpain-1/ Caspase-12 Pathways in Rat Brain After Long Time Exposure to GSM Radiation.

To investigate the potential protective effects of melatonin on the chronic radiation emitted by third generation mobile phones on the brain. A total of 24 male Wistar albino rats were divided into four equal groups. Throughout a 90-day experiment, no application was performed on the control group. The second group was exposed to 2100 MHz radiation for 30 minutes. Subcutaneous melatonin was injected into the third group. Subcutaneous melatonin injection was applied 40 minutes before radiation and then the fourth group was exposed to radiation for 30 minutes. At the end of the experiment, brain (cerebrum and cerebellum) tissues were taken from the subjects. Histochemical, immunohistochemical, ultrastructural and western blot analyses were applied. In addition to brain weight, Purkinje cells’ number, immunohistochemical H Score analyses and the results of the Western blot were examined statistically. With the application of radiation, neuronal edema, relatively-decreased numbers of neurons on hippocampal CA1 and CA3 regions, displacement of the Purkinje neurons and dark neurons findings were observed as a result of histochemical stainings. Radiation also activated the NMDA-receptor 2B/Calpain-1/Caspase-12 pathway, NMDA-receptor 2B and Calpain-1 with the findings being supported by western blot analyses. Pre-increased protein synthesis before apoptosis was identified by electron microscopy. Mobile phone radiation caused certain (ultra) structural changes on the brain and activated the NMDA-receptor 2B/ Calpain-1/Caspase-12 pathway; in addition, melatonin was found to be effective, but insufficient in demonstrating the protective effects.

5 GHz laterally‐excited bulk‐wave resonators (XBARs) based on thin platelets of lithium niobate

In a free-standing 400-nm-thick platelet of crystalline ZY-LiNbO 3 , narrow electrodes (500 nm) placed periodically with a pitch of a few microns can eXcite standing shear-wave bulk acoustic resonances (XBARs), by utilising lateral electric fields oriented parallel to the crystalline Y -axis and parallel to the plane of the platelet. The resonance frequency of ~4800 MHz is determined mainly by the platelet thickness and only weakly depends on the electrode width and the pitch. Simulations show quality-factors ( Q ) at resonance and anti-resonance higher than 1000. Measurements of the first fabricated devices show a resonance Q -factor ~300, strong piezoelectric coupling ~25%, (indicated by the large Resonance-antiResonance frequency spacing, ~11%) and an impedance at resonance of a few ohms. The static capacitance of the devices, corresponds to the imaginary part of the impedance ~100 Ω. This device opens the possibility for the development of low-loss, wide band, RF filters in the 3-6 GHz range for 4th and 5th generation (4G/5G) mobile phones. XBARs can be produced using standard optical photolithography and MEMS processes. The 3rd, 5th, 7th, and 9th harmonics were observed, up to 38 GHz, and are also promising for high frequency filter design.

Short-term radiofrequency exposure from new generation mobile phones reduces EEG alpha power with no effects on cognitive performance

Although mobile phone (MP) use has been steadily increasing in the last decades and similar positive trends are expected for the near future, systematic investigations on neurophysiological and cognitive effects caused by recently developed technological standards for MPs are scarcely available. Here, we investigated the effects of radiofrequency (RF) fields emitted by new-generation mobile technologies, specifically, Universal Mobile Telecommunications System (UMTS) and Long-Term Evolution (LTE), on intrinsic scalp EEG activity in the alpha band (8–12 Hz) and cognitive performance in the Stroop test. The study involved 60 healthy, young-adult university students (34 for UMTS and 26 for LTE) with double-blind administration of Real and Sham exposure in separate sessions. EEG was recorded before, during and after RF exposure, and Stroop performance was assessed before and after EEG recording. Both RF exposure types caused a notable decrease in the alpha power over the whole scalp that persisted even after the cessation of the exposure, whereas no effects were found on any aspects of performance in the Stroop test. The results imply that the brain networks underlying global alpha oscillations might require minor reconfiguration to adapt to the local biophysical changes caused by focal RF exposure mimicking MP use.

Electromagnetic Noise Suppression Composite Sheets Made of Hexagonal Ferrite Particles

In the early stage 5th generation mobile phone system, it is expected to use high frequencies up to the SHF band (3 to 30 GHz) [1]. Therefore new noise countermeasure material is necessary in this band [2]. In this paper, we studied M-type, Y-type and Z-type hexagonal ferrite fine particles in composite form with epoxy resin, to find candidate for this application through SEM observation, XRD, DC hysteresis loop, high frequency complex permeability, and conduction noise suppression effect on micro stripline(MSL).Preparation and properties of fine particles– While Sr and Ba hexagonal ferrite materials are known as permanent magnet materials, they are also useful as high frequency materials whose ferromagnetic resonance (FMR) frequency exceeds 20 GHz, which corresponds to the center frequency of noise suppression exceeds 20 GHz. Firstly we followed a known direction to reduce magneto-crystalline anisotropy by a 1 – 2 at% substitution of Fe3+ions by a combination of metal ions such as Co2+and Ti4+. Table Ishows list of test perticles; Z-type Ba 3 Zn 2−X Co x Fe 24 O 41 (x=1.25), Y-type Ba 2 Zn 2 Fe 12 O 22 , and M-type SrCo x Ti x Fe 2−x O 19 (x=1.4) [3]. The fired polycrystalline material was pulverized to obtain fine particles. The XRD pattern showed that the crystal structure is mainly composed of hexagonal crystals since the relative intensity and diffraction angle of the main diffraction peak agree with the values of the JCPDS database.Fabrication and properties of composite sheet– The fine particles were mixed with the epoxy resin at a volume ratio of about 50%. This mixed solution was dropped onto a polymer sheet and screen-printed with a metal squeegee to a certain thickness, then a composite sheet was obtained. On the premise of mounting the composite in the gap between the interposer substrate and the IC chip, the coating thickness was chosen as 50 ± 5 μm in total. The Y-type fine particles were almost flat in planar state even after grinding and the Z-type and M-type fine particles were close to spherical and randomly oriented, according to the SEM observation. The coercive force obtained from the DC magnetization curve is 8 to 9 Oe in a composite sheet of Y-type and Z-type fine particles (hereinafter referred to as Y-type sheet, etc.), which is smaller by one order of magnitude than the M-type sheet (90 Oe). Correspondingly, the maximum value of the relative imaginary part permeability was the maximum of 1.8 for the Y-type sheet, and it was 0.9 for the Z-type sheet, and 0.3 for the M-type sheet. As shown in Fig. 1, measured input loss ratio [4] $\mathrm {P}_{{\mathrm {loss}}}/ \mathrm {P}_{{\mathrm {in}}}=1- ( \vert \mathrm {s}_{11} \vert ^{2}+\vert \mathrm {s}_{21} \vert ^{2})$with a network analyzer (Agilent Technologies, Model N5244A) became the larger as the relative imaginary part magnetic permeability became higher. The measured $\mathrm {P}_{\mathrm {loss}}/ \mathrm {P}_{\mathrm {in}}$was as high as 0.21 at 6 GHz, which should correspond to more than 5 dB conduction noise suppression. This research was supported in part by the R&D program of the Radio Use, Ministry of Internal Affairs and Communications, and the Cooperative Research Project Program of the RIEC (H27-B05) Tohoku University.

Next Generation Mobile Phone Antenna and its SAR Investigation

This work presents the design and Specific Absorption Rate (SAR) investigation of Fifth Generation (5G) antenna for future mobile communication networks. The radiating patch is made up of copper material backed by a 0.254 mm thicker Roggers-5880 substrate (N9000 PTFE) having relative permittivity and loss tangent of 22x10-1 and 9x10-4, correspondingly. The antenna resonates at 23 GHz frequency band. The major lobe gain of the single component 5G antenna is 7.16 dB.To meet the gain requirements of 5G mobile communication systems, 1 x 4 element array antenna has been proposed which increases the bore side gain up to 12.6 dB at the desired frequency. The proposed antennas efficiency is 91-94 % with a sufficient amount of driving point impedance bandwidth (S11<- 10 dB), i.e. 600-620 MHz;The SAR of the proposed antenna is analyzed at two different parts of human body, i.e. belly and hand. The SAR is averaged over 10g of tissue. The proposed 1 x 4 element antenna gives lower values of SAR (<2 W/kg) on all parts of human body. The proposed array antenna can be used in 5G mobile handheld devices. All the simulations are carried out using CST MWS. The proposed antenna is suitable contender for 5G mobile communication systems.

Thermoluminescence of chip inductors and resistors in new generation mobile phones for retrospective accident dosimetry

Luminescence dosimetric properties of inductors and resistors in mobile phones have attracted wide attention for their use in retrospective accident dosimetry. Thermoluminescence (TL) signal following optically stimulated luminescence (OSL) readout, which has been recently shown to be useful for dose re-estimation (Lee et al., 2016), when measured by a Risoe OSL reader without a Hoya U-340 optical filter, was found to be up to 85 times of that recorded with the Hoya filter (with transmission window 270–380 nm, necessary for recording the usual OSL signal) placed in front of the photomultiplier tube (PMT) in the reader. In view of this, a study of dosimetric TL properties, namely sample-to-sample variation, fading, zero-dose signal, minimum measurable dose, effect of room light, dose response and emission spectrum, was undertaken to explore the use of TL of inductors and resistors in new generation mobile phones for accident dosimetry. The hitherto unknown TL emission spectrum was found to exhibit an intense emission beyond 550 nm (peaking at 700 nm) when recorded in the range from 250 nm to 750 nm. Emission below 500 nm was smaller by orders of magnitude than that at 700 nm. As the TL and OSL signals have been attributed to alumina substrates of inductors and resistors, the TL emission spectrum was compared with that of dosimetry grade Al2O3:C. The emission spectra of inductors and resistors were found to differ significantly, not only from that of Al2O3:C, but also from each other. Although the differences in TL glow curves, optical emission spectra, fading, etc. Indicated a lack of universality in luminescence properties of alumina substrates in different electronic components, it was concluded that the TL of inductors and resistors in new generation mobile phones offers a better option for accident dosimetry than OSL, with the specific advantage of much lower post-irradiation fading.

Analysis Randomness Properties of Basic Components of SNOW 3G Cipher in Mobile Systems

Abstract— SNOW 3G is a stream cipher algorithm used as encryption algorithm in third generation mobile phone technology (3G-UMTS). In this paper, we analyzed and evaluated the randomness properties of basic components of SNOW 3G cipher. NIST test suit (SP 800-22) used in evaluating and testing the randomness properties. We conducted statistical tests on various components of SNOW 3G cipher such as keystream, Finite State Machine, S-boxes S1 and S2, registers (R1, R2, and R3), and Linear Feedback Shift Register. Our experimental results and empirical analysis shown that SNOW 3G cipher passed statistical randomness tests.

Features of equalization in LTE technology with MIMO and SC-FDMA

The Long Term Evolution (LTE) is one of communication standards for next-generation mobile phones, which has evolved the high-speed data communication standard HSDPA for the mainstream 3G (third generation) mobile phone system W-CDMA at present. Data communication volume of mobile phones is rapidly increasing at present due to dissemination of smart phones and mobile communication. Therefore, expansion of communication band (capacity) is a critical issue for communication carriers. Because the LTE that allows high-speed data communication with low delay is superior in terms of the radio wave use efficiency, many of major communication carriers in the world have indicated a policy of adopting the LTE. The rapid dissemination of the LTE in the future is expected. In this report we overview the fundamental techniques of equalization in LTE technology with MIMO and SC-FDMA in channels where the maximum delay exceeds the length of the Guard Interval. The goal of employing narrow band subcarriers is to obtain a channel that is roughly constant over each given sub band, which makes equalization much simpler at the receiver. There are considering advantage and disadvantage three types equalization techniques: time domain, frequency domain and turbo equalization. On base of these compeering are giving practical recommendation for choice method of equalization. To enhance this frequency use efficiency, antenna technologies, including Multi Input Multi Output (MIMO) that allows transmission/reception with multiple antennas and Space Division Multiple Access (SDMA) that allows multiple access between base stations, have been introduced. Furthermore, Orthogonal Frequency Division Multiple Access (OFDMA) and Single Carrier Frequency Division Multiple Access (SC-FDMA) are used as multiplexing systems.

Does the Brain Detect 3G Mobile Phone Radiation Peaks? An Explorative In-Depth Analysis of an Experimental Study.

This study aimed to investigate whether third generation mobile phone radiation peaks result in event related potentials. Thirty-one healthy females participated. In this single-blind, cross-over design, a 15 minute mobile phone exposure was compared to two 15 minute sham phone conditions, one preceding and one following the exposure condition. Each participant was measured on two separate days, where mobile phone placement was varied between the ear and heart. EEG activity and radiofrequency radiation were recorded jointly. Epochs of 1200ms, starting 200ms before and lasting until 1000ms after the onset of a radiation peak, were extracted from the exposure condition. Control epochs were randomly selected from the two sham phone conditions. The main a-priori hypothesis to be tested concerned an increase of the area in the 240-500ms post-stimulus interval, in the exposure session with ear-placement. Using multilevel regression analyses the placement*exposure interaction effect was significant for the frontal and central cortical regions, indicating that only in the mobile phone exposure with ear-placement an enlarged cortical reactivity was found. Post-hoc analyses based on visual inspection of the ERPs showed a second significantly increased area between 500-1000ms post-stimulus for almost every EEG location measured. It was concluded that, when a dialing mobile phone is placed on the ear, its radiation, although unconsciously, is electrically detected by the brain. The question of whether or not this cortical reactivity results in a negative health outcome has to be answered in future longitudinal experiments.

On the use of new generation mobile phone (smart phone) for retrospective accident dosimetry

Abstract Optically stimulated luminescence (OSL) characteristics of resistors, inductors and integrated-circuit (IC) chips, extracted from new generation smart phones, were investigated for the purpose of retrospective accident dosimetry. Inductor samples were found to exhibit OSL sensitivity about 5 times and 40 times higher than that of the resistors and the IC chips, respectively. On post-irradiation storage, the resistors exhibited a much higher OSL fading (about 80 % in 36 h as compared to the value 3 min after irradiation) than IC chips (about 20 % after 36 h) and inductors (about 50 % in 36 h). Higher OSL sensitivity, linear dose response (from 8.7 mGy up to 8.9 Gy) and acceptable fading make inductors more attractive for accident dosimetry than widely studied resistors.